1. Technical Field
The present invention relates to an electronic device and a method for manufacturing an electronic device.
2. Related Art
Electronic devices having exposed portions in functional elements are being developed for practical uses to meet the needs in recent technological advances. The developments of such type of devices are based on requirements for reducing an attenuation of an optical signal and an improved moisture resistance of electronic devices for meeting with a reflow condition in mounting a lead free by employing a black resin in an electronic device that converts an optical signal into an electrical signal and directly introduces an optical signal entered from an outside of the electronic device into a photo acceptance of the optical device. In particular, in optical recording technologies utilizing blue light as an optical signal, epoxy resins employed in light-receiving devices for transforming the optical signals into electrical signals are deteriorated by the blue light to be in failure condition, and therefore, the above-mentioned electronic devices having exposed portions in functional elements, in which epoxy resin is eliminated from the optical path, are required. In addition, the electronic devices having such structure include movable elements in functional elements such as micro electro-mechanical systems (MEMS), electric acoustic filters and the like, and the above-described types of electronic devices are expected to be adopted for devices having movable elements that cannot be encapsulated with a resin or for solid-state image sensing elements for cameras.
FIG. 12 is a cross-sectional view, illustrating a solid-state imaging device described in Japanese Patent Laid-Open No. 2001-257,334. As shown in FIG. 12, a solid-state imaging device includes a solid-state image sensing element chip 81, an epoxy resin sheet 84 having an opening portion 83 formed only in a photo acceptance unit (not shown) adhered on the solid-state image sensing element chip 81 with an adhesive agent 85, and a transparent member 86 adhered on the epoxy resin sheet 84 with the adhesive agent 85 and serving as a flat plate portion. The solid-state image sensing element chip 81 is die-bonded to a package or substrate 810, and certain couplings between a pad portion 81a of the solid-state image sensing element chip 81 and the package or substrate 810 are made by bonding wires 811 to achieve a practical use thereof, and then peripheral portions thereof including bonding wire-coupling portions except hermetic seals are packaged with an encapsulating resin 812. A transparent member 86 functions as a protective film for a photo acceptor.
FIG. 13, 14 are cross-sectional views, illustrating a solid-state imaging device described in Japanese Patent Laid-Open No. H07-202,152 (1995). As shown in FIG. 13, a solid-state imaging device includes a solid-state image sensing element chip 91, in which only a photo acceptance area 92 provided with a micro lens 93 is hermetically sealed with a transparent encapsulating member 94. The solid-state image sensing element chip 91 is directly adhered onto a substrate 921 by a die-bonding, and after the electrodes of the solid-state image sensing element chip 91 is connected to the electrodes of the substrate 921 by the bonding wires 922, the chip surfaces except the transparent encapsulating member 94 provided only in the photo acceptance area 92 of the solid-state image sensing element chip 91 and the coupling portions with the bonding wires 922 are encapsulated with the encapsulating resin 923. As shown in FIG. 14, the transparent encapsulating member 911 includes a flat plate portion 911a and a frame 911b and is configured to form the flat plate portion 911a on the upper surface of the frame 911b. The transparent encapsulating member 911 provides a protection of the photo acceptance area 92, and the flat plate portion 911a functions as a protective film. A transparent encapsulating member 911 shown in FIG. 14 corresponds to the transparent encapsulating member 94 shown in FIG. 13.
Besides, the upper surface of the encapsulating resin 812 is located to be higher than the upper surface of the epoxy resin sheet 84 in the solid-state imaging device described in reference to FIG. 12. Therefore, the side surfaces of the transparent member 86 formed on the epoxy resin sheet 84 are covered with the encapsulating resin 812. This provides an adhesion of the side surface of the transparent member 86 with the encapsulating resin 812, and thus stripping of the transparent member 86 is difficult.
In the solid-state imaging device described in reference to FIGS. 13 and 14, the upper surface of the encapsulating resin 923 is located to be higher than the upper surface of the frame 911b. Since the side surface of the transparent encapsulating member 94 is covered with the encapsulating resin 923 as shown in FIG. 13, the side surface of the flat plate portion 911a shown in FIG. 14 is covered with the encapsulating resin 923 (not shown). This causes an adhesion of the side surface of the flat plate portion 911a with the encapsulating resin 923, causing a difficulty in stripping the flat plate portion 911a. In addition, since the dimensional area of a surface for adhesion of the flat plate portion 911a is limited by the dimensional area of the upper surface of the frame 911b, it is difficult to provide an increased dimensional area for adhesion to achieve higher adhesive force.